Why Some Guys' Semen Tastes Funky

Our collective gag reflex kicks in just thinking about it: You’re going down on a guy, everything’s going great, and then you get torpedoed in the back of your throat with something that tastes like, well, nothing short of hell.

While scientists have yet to examine what gives each guy his unique flavor, be it good or bad, theoretically, it has a lot to do with his health and diet, says Brian L. Steixner, M.D., director of the Institute for Men’s Health at the Jersey Urology Group.

About 95 to 98 percent of semen isn’t sperm. Most of it is water, fructose (why ejaculate contains between five and 25 calories, on average), enzymes, minerals, and compounds that keep sperm healthy and help them find your egg, says Steixner. The greatest changes to this ingredient list come (ha!) when guys are dealing with prostate cancer, STDs, and urinary tract infections (yup, guys can get them, too). They can add bacteria, viruses, or even blood into the mix. Obviously, these are all cause for concern—and it's worth making sure your guy's visited the doctor recently if you notice his jizz suddenly starts tasting foul.

However, for the average, everything’s-in-working-order guy, the above spluge breakdown is pretty strictly regulated. Men can’t really increase the amount of sugar in their semen, says Steixner, which is why doing things like chugging pineapple juice isn't going to be a quick fix for funky spunk.

“Guys can’t really change the components, but dehydration can increase their concentration,” says Steixner. “It’s like with urine; when you are dehydrated, there is less water in your pee, so it’s darker yellow and maybe it smells a little bit.” The body only has so much water to live on, so it prioritizes keeping guys’ brains hydrated over their semen (thankfully). “I tell guys they always need to get at least two liters of water a day between what they drink and what they eat. Vegetables like celery and cucumbers help keep semen’s water content where it needs to be,” says Steixner.

Meanwhile, while it hasn’t been studied, drinking alcohol, eating junk food, smoking, or loading up on garlic, onion, asparagus, and cumin could possibly contribute to bad down-there taste, he says. After the body breaks them down, they often wind up in body secretions like sweat and spit—so why not spluge?

Once you rule out any serious below-the-belt problems in your guy, try simpler fixes: Give him a cool water bottle he'll be amped to use, fill the fridge with celery, and try to keep him away from onion-heavy dishes as much as possible.